The present invention relates to horns for generating an audible signal or alarm.
By way of example, fire detectors for sensing smoke or the products of combustion include a horn to sound an audible alarm so a fire will not go undetected for lack of immediate visual supervision, and so all personnel within hearing range of the alarm will be alerted to the danger. Such audible alarm is essential in environments such as homes, where immediate supervision is customarily lacking while the occupants are asleep.
It is not only desirable, but necessary, that the audible alarm generating horn be both efficient, to generate a very loud alarm, and reliable, to generate and continue generating an alarm every time and for as long as power is supplied to it. Therefore, horns of the general type should ideally be configured to maximize the sound level of the alarm generated thereby, and be designed to assure reliability.
In addition, the horns must be of small size because they are customarily confined within a small space, for example a relatively small household appliance such as a fire detector to be mounted on the wall or on the ceiling in a home; and they must also be of very economical construction to avoid pricing the appliance outside the economic reach of the general consumer.